Aerosol dispensing and similar metal cans adapted to contain a pressurized fluid

ABSTRACT

A metal aerosol dispensing can has a cylindrical side wall and a separate bottom fitted to the side wall by a rolled joint including overlapping edges of the bottom and of the side wall. After forming the joint, the bottom and joint are pushed wholly within the cylindrical side wall, the lower part of the side wall thus being folded inwardly. The folded parts of the side wall can then be inwardly deformed to form a rim supporting the joint.

United States Patent Dolveck Nov. 25, 1975 [5 AEROSOL DISPENSING AND SIMILAR 2.384 042 9/1945 OBrien 220/67 METAL cANs ADAPTED T0 CONTAIN A 3:32? 2 aun ers.... PRESSURIZED FLUID 3,698,596 10/1972 Potts [75] inventor: Gilbert Dolveck, St. 3,70 ,398 l/l973 Fuhrmanm.

Barthelemy-de-Beau epaire France X [73] Assignee: Aluminium Suisse S.A., Switzerland Primary Examiner john Petrakes [22] Filed: De 3, 1973 Attorney, Agent, or Firm-Robert E. Burns;

1 B PP o: 42 09 Emmanue J Lobato, ruce L Adams [57] ABSTRACT Application Priority Data A metal aerosol dispensing can has a cylindrical side Dec. 4, 1972 Switzerland 17610/72 wall and a separate bottom fitted to the side wall by a rolled joint including overlapping edges of the bottom [52] US. Cl. 220/67; 220/78; 220/79 and of the side wall. After forming the joint, the bot- [51] Int. Cl. B65D 7/36; B65D 7/42 tom and joint are pushed wholly within the cylindrical [58] Field of Search 220/66, 67, 77-79 side wall, the lower part of the side wall thus being folded inwardly. The folded parts of the side wall can [56] References Cited then be inwardly deformed to form a rim supporting UNITED STATES PATENTS the j l,559,096 10/1925 Hall 220/78 4 Claims, 4 Drawing Figures U.S. Patent Nov. 25, 1975 FIG. 1

Sheet 1 of 2 FIG. 2

US. Patent Nov. 25, 1975 Sheet2of2 3,921,848

FIG. 4

FIG. 3

AEROSOL DISPENSING AND SIMILAR METAL CANS ADAPTED TO CONTAIN A PRESSURIZED FLUID The invention relates to metal cans with fitted bottoms ie in which a bottom is fitted and fixed to a tubular side wall for example by providing a spun seam, adapted to contain a pressurized fluid in the form of a liquid, pulverulent or-pasty product and/or agas under pressure, for example aerosol dispensing cans.

Aerosol dispensing cans having a bottom made in one piece with a tubular side wall are known. The possibilities of shaping the upper parts of such cans are however very limited and it is notably difficult with present-day techniques to form a trunco-conical upper part making a distinct angle with a cylindrical lower part of the wall. Also, it is difficult to provide one-piece cans in a material other than aluminium since narrowing of a neck portion presents difficulties. For these reasons, cans with fitted bottoms are still in great demand.

However, the lower parts of known cans with fitted bottoms do not have the smooth and uniform aspect of one-piece cans, but the joint or seam is apparent. A

first improvement has been provided by making the outer diameter of the joint or seam the same as the outer diameter of the cylindrical wall in a manner to eliminate a protuberance which forms an impedance notably when the package is handled. The joint nevertheless remains visible, and is not only inaesthetic but still forms a seat in which dirt can accumulate at a location liable to contact with the users hand, which is often undesirable for example for disinfectant aerosol sprays for use by dentists or doctors.

An aim of the present invention is to provide a can with a fitted bottom in which the joint between the bottom and the side wall is concealed and out of the way of a users hand during normal use.

According to the invention, there is provided an aerosol dispensing or similar metal can adapted to contain a pressurized fluid, comprising a tubular side wall having a circular cross-section, and a separate bottom fitted to the side wall by a joint including overlapping edges of the bottom and of an inwardly folded over portion of the side wall, the bottom and joint being disposed wholly within an outer part of the side wall adjacent said inwardly folded over portion.

The invention also provides a process for manufacturing an aerosol dispensing or similar metal can adapted to contain a pressurized fluid, comprising providing a tubular side wall having a circular cross-section, inwardly deforming an end part of said side wall to form a groove, fitting a bottom at said end part by forming a rolled joint including overlapping edges of the bottom and groove-forming part of the side wall, the outermost part of said rolled joint being formed by the bottom and having an outer diameter at most equal to the outer diameter of an undeformed part of the side wall adjacent to said groove reduced by approximately four times the thickness of the side wall, and pushing the bottom together with the rolled joint wholly inside an undeformed part of the side wall.

Surprisingly, no weakening of the joint nor breakage of the metal is produced when the bottom is pushed in, as could be expected.

It is even possible to sufficiently push the bottom into the can to enable the adjacent outer part and inwardly folded over portion of the side wall to be folded inwards relative to an adjacent nondeformed part of the side wall to form a rim bearing against and supporting the joint, which enables, for an aluminium bottom fitted to a cylindrical wall of aluminium, the provision of a reinforced rolled joint for which the pressure of ripping off of the bottom is greater than the pressure of reverse snapping of the bottom. This condition was only previously possible to achieve using a tin bottom.

The accompanying drawings show, by way of example, an embodiment of the invention during various stages of its manufacture. In the drawings:

FIGS. 1, 2, 3, 3a, 4, and 4a are side elevational views, partly in crosssection, and with enlarged-scale crosssectional details of the lower edge, showing a can during four stages of the manufacture thereof.

With reference to FIGS. 1 and 1a, at the base ofa tubular envelope of aluminium, produced by stamping, having a cylindrical side wall 1, a trunco-conical upper end 2 and a rolled edge 3 adapted to receive a valve by the so-called beading method, there is formed a groove 4 by inwardly deforming part of wall 1, the diameter of the lower edge 5 of groove 4 being approximately equal to the inner diameter of the wall 1.

On the edge 5 is then applied a bottom 6 having a central dished part 6a, a cylindrical wall 6b, an outwardly projecting flange 6c and an upturned edge 6d approximately parallel to the cylindrical wall 612. This bottom 6 is fixed by a conventional setting or spinning operation, the flange 6c thus being bent upwardly, looking at the drawing,'and forming the outer part of a rolled joint or seam. The size of bottom 6 in relation to the wall 1 is chosen so that its outer diameter, after setting or spinning, is at most equal to the outer diameter of the undeformed cylindical wall 1 reduced by four times the thickness of this wall. In other words, the outer part of bottom 6 after setting or spinning is radially set back from the outer face of wall 1 by at least about twice the thickness of wall 1, as shown in the detail of FIGS. 2 and 2a, whereas the depth and the shape of the neck 4 are such that this neck mates with the shape of the wall 6b and rolled over flange 6c of bottom 6, in a manner to permit pressing of the edge of bottom 6 into wall 1 to ensure a satisfactory joint.

In a third stage, shown in FIGS. 3 and 3a, the bottom 6 is pressed into the end of wall 1 by exerting a pressure on bottom 6 in the direction of arrow F by means of a tool having a rounded head corresponding to the curvature of bottom 6. During this operation, the rolled joint is driven by bottom 6 inside the wall 1 without ripping or apparent weakening. The wall 1 in effect deforms in a manner to follow the displacement of the joint, forming a fold 7. The formation of this fold is made possible by the selected relative dimensions of the-bottom 6 and wall 1.

In the position shown in FIGS. 3 and 3a, the rolled joint is already concealed inside cylindrical wall 1 and it would be possible to employ such a can.

It is however preferred, as shown in FIGS. 4 and 4a,

to inwardly deform fold 7, formed by the adjacent outer part and inwardly folded over portion of the wall, to form a rim 7' which partly covers and supports the rolled joint, thereby reinforcing the securing of bottom 6. The rolled joint comes to bear on rim 7' so that to cause ripping off of the bottom, the pressure inside the can must firstly deform this rim 7' and push the bottom into the position shown in FIG. 2 before acting on the joint. It can thus easily be appreciated that the bottom will reverse snap well before being ripped off, which is a condition generally required for aerosol dispensing cans.

What is claimed is:

l. A can for containing a pressurized fluid comprising, a tubular body, an inwardly concave bottom having a peripheral outward reverse fold fixed to said body and closing the bottom of said tubular body, said tubular body having a sidewall annular in cross section with a lower marginal portion reversely folded inwardly of the can extending away from a lower fold and including a fold overlapping the outward reverse fold of said bottom and jointly therewith defining a seam axially spaced inwardly from said lower fold fixing the bottom to the tubular body, said lower fold extending radially inwardly of the can body it underlies defining an inner diameter of the lower fold progressively decreasing in a direction away from said bottom, and said bottom hav- 4 ing a greater outer diameter than the minimum inner diameter of said lower fold, whereby said lower fold coacts with said scam in fixing the bottom axially on said body.

2. A can for containing a pressurized fluid according to claim 1, in which said reverse fold partially underliesv and are in contact. 

1. A can for containing a pressurized fluid comprising, a tubular body, an inwardly concave bottom having a peripheral outward reverse fold fixed to said body and closing the bottom of said tubular body, said tubular body having a sidewall annular in cross section with a lower marginal portion reversely folded inwardly of the can extending away from a lower fold and including a fold overlapping the outward reverse fold of said bottom and jointly therewith defining a seam axially spaced inwardly from said lower fold fixing the bottom to the tubular body, said lower fold extending radially inwardly of the can body it underlies defining an inner diameter of the lower fold progressively decreasing in a direction away from said bottom, and said bottom having a greater outer diameter than the minimum inner diameter of said lower fold, whereby said lower fold coacts with said seam in fixing the bottom axially on said body.
 2. A can for containing a pressurized fluid according to claim 1, in which said reverse fold partially underlies said outward reverse fold of said bottom.
 3. A can for containing a pressurized fluid according to claim 2, in which said lower fold of said body is axially spaced from said outward reverse fold of said bottom.
 4. A can for containing a pressurized fluid according to claim 2, in which said lower fold of said body and said reverse fold of said bottom have a same curvature and are in contact. 